Hi all, I'm working on a late 70's John deere 690B trackhoe, I bought a hydraulic thumb for it and need to add hookups for it. From my research my options are: 1. T into hydraulic lines going to turntable with a double selector valve like this: http://www.surpluscenter.com/Hydrau...LE-SELECTOR-VALVE-12VDC-P15438-2-9-7738-A.axd 2. Tap into the main oil supply and add a SUBPLATE & DO3 Electric over hydraulic direcdtional control valve http://www.northmanfp.com/24501.html 3. Possibly you could tell me where/& how the best way is to tap into the factory system Please tell me what my best option is!! thanks
Boy that brings back memories, we did this 25 years ago. Ill see if the manual is still around, we made a page of mods and parts. No guarantees but ill check I do know you will need a circuit relief for that function and a crossover relief set to whatever will let the bucket push it back , or you will break a lot of stuff.
I have one of these multiplier valves already sitting on the shelf...hopefully I can utilize it http://www.shoupparts.com/700-1002/
OK did a little research in my technical manual, the 690b is a open center system, 2500psi max, 18GPM. I'm tapping into the open center supply line & tank return lines, going to a DO5 subplate mounted tandem center Directional control valve , then to a Double relief valve (cushion valve) and then to thumb cylinder (double acting) Will mount a momentary on/off/on rocker switch on the stick lever. northerntool.com Northman Fluid Power Hydraulic Directional Control Valve – 26.4 GPM, 4500 PSI, 3-Position, Double Solenoid, Tandem Center Spool, 12 Volt DC Solenoids, Model# SWH-G03-C6-D12-10 The price is $139.99 Item# 202505 Northman Fluid Power Single-Station Subplate — NFPA D05 Pattern, 3/4in. NPT Side Ports, Model# M03-06-S-2 $59.99. Item# 203361 Surpluscenter.com 3/4 NPT 30 GPM 1500-3000 PSI HYD CUSHION VALVE ITEM NUMBER: 9-4019-75-H PRICE: $70.95 $285 total so far, + hydraulic hoses & fittings (estimated $400)+ $3000 new gentec HT2650 thumb that I picked up for $900 I'm going to have the local triad parker store (hydraulic supply store) service truck guy come out and measure up everything and create a hose & fittings parts list. HKX wanted 4-5k for a auxillary kit, and have never put one on a B model.
Are you sure it's 18 GPM Max? I don't know ANYTHING about a 690B but that seems very low to me... I have a Hitachi EX200-2, same size machine, and it is approx. 50 GPM max flow........
My book says Min 32gpm @2500psi (per section).
Good call. Yea the main output totals 64gpm but 18gpm available to boom/crowd/bucket circuit.... my 3/4 npt ports /26gpm valve is probably overkill for a 1/2npt cylinder port....1/2" id lines going up the boom should be big enough.
If I'm reading that right it says Priority flow. That would mean that up to 18 GPM is always available to the valve sections regardless of what the other functions are doing so that you can move those functions while travelling for instance... Someone correct me if I'm wrong, but to me it sounds like that flow is there when travelling, when not travelling you get the full 64GPM...
You do NOT want to use that cushion valve with a double acting cylinder, you need either a pair of single relief valves plumbed to tank or a crossover relief with the vents tied to a tank port. With a thumb cylinder and a straight crossport relief when you crowd the thumb you get pressure multiplication and the weakest link, be it hose, valve, or cylinder tube, turns into a bomb. Technically you also need anti-cavitation checks or the cylinder will probably suck air at the rod gland, a proper relief manifold from SUN or other will have them built in. :IMO
So I talked to a JD service manager at the local dealership, and he said I couldn't T into any of the lines because my 20gpm valve would restrict the flow too much..........any ideas? & so that cushion valve is only for single acting cylinders?